A solid oxide fuel cell device (“SOFC” below) is a fuel cell device for generating electricity by causing an electrical generating reaction to take place at a relatively high temperature by use of an oxide ion electrically conductive solid electrolyte as an electrolyte, with electrodes attached on both sides thereof, and with fuel gas supplied to one side thereof and air supplied to the other side thereof.
In fuel cell device of this type, the amount of electrical power obtained from a single fuel cell (single cell) is small, therefore the required electrical power is obtained by arraying multiple fuel cells in parallel and connecting these in an electrically serial form using a current collecting member, as shown in Patent Citations 1-3.
Patent Document 1 discloses, an air electrode (+ pole) is formed on the inner circumferential surface of an electrolyte formed in a cylindrical shape, and a fuel electrode (− pole) is formed on the outer circumferential surface thereof and the air electrode on the inner circumferential surface is extended cylindrically from solid electrode at its end. In the fuel cell of this Patent Document 1, multiple fuel cells (single cells) are arrayed in parallel inside a housing, and the open portion of the housing is hermetically sealed so that fuel gas supplied to the interior of the housing does not leak out. A current collector is attached to the outer circumferential surface of each single cell; the end portion of this current collector extends airtightly from the glass on one side of the air electrode and is connected to the air electrode in the adjacent single cell via a connecting current collecting member. In the fuel cell of Patent Citation 1, a solid oxide fuel cell is formed by thus serially connecting multiple single cells in a stack.
Patent Document 2 discloses a fuel cell (single cell) in which a fuel electrode (− pole) is formed on the inner circumferential surface of a solid electrolyte formed in a cylindrical shape and an air electrode (+ pole) is formed on the outer circumferential surface thereof, whereby an inner electrode (− pole) connected to the fuel electrode is formed on one end, and an outer electrode (+ pole) connected to the air electrode is formed at the other end thereof. In the solid oxide fuel cell of Patent Document 2, all of the 20 single cells, consisting of 5×4 rows, are serially connected. Specifically, multiple single cells are oriented in alternately opposite directions, and both end portions of the multiple single cells are positioned by support plates at both end portions thereof, with the inside electrode (− pole) and the outside electrode (+ pole) respectively serially connected at the respective support plate sides.
Patent Document 3 also discloses approximately the same type of fuel cell as Patent Document 2.